基于空气耦合超声波的非金属陶瓷材料检测研究

针对非金属陶瓷材料的空气耦合超声波检测问题,建立空气耦合超声波经空气入射非金属陶瓷材料的数学模型及非金属陶瓷材料的空气耦合超声波检测有限元模型,通过matlab软件和ANSYS有限元软件联合仿真得到了非金属陶瓷材料的空气耦合超声波检测的频散曲线和各节点的接收信号,研究了空气耦合超声波在非金属陶瓷材料中的传播特性.结果表明,当频厚积小于2 MHz· mm,空气耦合超声波在非金属陶瓷材料氮化硅材料中存在A0,S0,SH0三种模态;当频厚积大于2 MHz· mm时,材料中存在较多的模态.随着声波传播距离越远,所接收到的A0模态和S0模态的信号幅值越小,且A0模态较S0模态幅值大,因此宜激发A0模态的空气耦合超声波检测和评价非金属陶瓷材料.

Testing for Non-metallic Ceramic Materials Based on Air-coupling Ultrasonic Wave

Aiming at the problem of air-coupling ultrasonic testing for non-metallic ceramic materials, the mathematic model and the finite element model of air-coupled ultrasonic detection of non-metallic materials was established.Air-coupled ultrasonic propagation dispersion curve and received signals obtained from some node was simulated by the method of Matlab software and ANSYS finite element software, and the propagation characteristics of air-coupled ultrasonic wave in non-metallic ceramic materials were studied.The results show that wave of A0, S0 and SH0 modes in the S3N4 ceramic material as the frequency is less than 2 MHz· mm.When the frequency is larger than 2 MHz· mm, the kinds of wave model is more in the medium.As the distance of wave propagation increase, the received signal amplitude of the A0 modal and the S0 modal is smaller, and the amplitude of A0 modal is larger than amplitude of the S0 modal, so it should stimulate the A0 modal of air coupled ultrasonic for testing and evaluating non-metallic ceramic materials.